Various aspects of the enterotoxins produced by Bacillus cereus and Bacillus thuringiensis will be studied. The major objectives of the study will be, 1) to determine the nutritional and environmental factors affecting production of enterotoxin by toxigenic strains of B. cereus. This will include synthesis of toxin in both laboratory media and food systems. 2) Purification of the toxin will be undertaken to determine its properties, provide the antigen for antiserum production and to provide material for work on determining the mechanism of toxic activity. 3) Control of toxin synthesis by the cells will be investigated to determine whether the information for synthesis is extrachromosomally borne (as for E. coli toxin and possibly staphylococcal toxin) or is associated with a temperate bacteriophage (as is the case for C. botulinum type C toxin). 4) The development of an assay procedure which is more sensitive, specific, and rapid will be undertaken. This will involve a skin test for erythemal activity or increased skin capillary permeability. 5) An attempt will be made to develop a monospecific antiserum against the enterotoxin. If (when) this is accomplished toxigenic strains will be surveyed to determine whether the toxins produced are serologically identical or heterogenous. Sera will be prepared against each of the different enterotoxins encountered. Serological techniques such as single diffusion tests and the microslide procedure will be investigated to develop a rapid quantitative assay for the enterotoxin. 6) Procedures for the recovery and identification of enterotoxin in food materials will be developed. Initially, this will involve adding toxin to foods and quantitating recovery. Subsequently, foods in which B. cereus has grown will be examined for the presence of toxin.